Using SmartFoxServer extension to detect collisions?

I think I may just be thinking about this in the wrong way, but I can't seem to figure out how I would go about detecting collisions on the server-side to prevent cheating (so to see if the bullet actually hit the enemy). I assume I would setup an extension, but I still don't understand how the code in the extension would know if there was a collision between the projectile and the enemy object.

There's a slightly related Question: How would Servers access back-end data?. Doesn't have a specific answer, but does have some discussion on the topic.

We had a similar requirement - we wrote a unity editor script to export the telemetry to an XML file the java extension could work with. It doesn't scale well to complex scenes / physics though - be sure to profile SmartFox during play.